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K A Christensen

Publications and source records attributed to K A Christensen.

4 recordsLinked to original sources
PubMed1979

Investigations on the activation of bovine prochymosin.

Activation of prochymosin at pH below 2.5 results in formation of the active enzyme pseudochymosin by proteolytic cleavage of the bond 27--28. Pseudochymosin is 15 amino acid residues longer than chymosin. It is the final activation product at low pH, whereas chymosin is formed by activation between pH 4 and 5. Pseudochymosin is converted to chymosin when it is brought to pH 5.5. Our present knowledge does not allow quantitative evaluation of the possible reactions involved in formation of pseudochymosin, but the course of activation at pH 2 is in accordance with an intermolecular reaction between two zymogen molecules as the predominant reaction. We find indications of an intramolecular reaction when intermolecular reactions are prevented by immobilization of the zymogen.

Amino Acid Sequence↗
PubMed1979

A syndrome with lack of udder developments in a high-yielding Jersey herd.

A syndrome with lack of udder development in a high-yielding jersey herd is described. The syndrome first appeared in the herd about 10 years ago. To try to elucidate this syndrome the endocrine pattern visualized by serum estrogen (Fig. 1) and progesterone (Fig. 2) levels was followed in 12 parturient cows. One case of typical lack of udder development appeared and was followed up by slaughter and pathological and histological examinations (Fig. 3 and 4). Pedigree investigations indicated that genetics could be involved in the syndrome. The endocrine pattern observed combined with the lack of udder development seems to indicate a complex disorder in the hormonal regulation which trigger the maternal preparation and initiation of parturition.

Animals↗